LIGNOPHYTA

True roots +; lateral meristems: cork cambium producing cork abaxially, vascular cambium producing phloem abaxially and xylem adaxially.

EXTANT SEED PLANTS/SPERMATOPHYTA

Plant woody, evergreen; nicotinic acid metabolised to trigonelline, (cyanogenesis via tyrosine pathway); primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignins derived from (some) sinapyl and particularly coniferyl alcohols, thus containing p-hydroxyphenyl and guaiacyl lignin units, (lignins derived from p-coumaryl alcohol, i.e. S [syringyl] lignin units); true roots present, apex multicellular, xylem exarch, and branching endogenous; arbuscular mycorrhizae +; shoot apical meristem multicellular, interface specific plasmodesmatal network; stem with ectophloic eustele, endodermis 0, xylem endarch, branching exogenous; vascular tissue in t.s. discontinuous by interfascicular regions; vascular cambium + [xylem ("wood") differentiating internally, phloem externally]; wood homoxylous, tracheids and rays alone, tracheid/tracheid pits circular, bordered; mature sieve tube/cell lacking functioning nucleus, plastids with starch grains; phloem fibres +; stem cork cambium superficial, root cork cambium deep seated; leaves with single trace from sympodium ["nodes 1:1"]; stomata ?; leaf vascular bundles collateral; leaves megaphyllous [determinancy evolved first, then ad/abaxial symmetry], spiral, simple, lamina with vein density up to 5 mm/mm² [mean for all non-angiosperms 1.8]; axillary buds associated with at most some leaves; prophylls [including bracteoles] two, lateral; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated in indeterminate cones/strobili; true pollen [microspores, i.e. no distal pore for release of gametes] +, grains mono[ana]sulcate, exine and intine homogeneous; ovules unitegmic, crassinucellate, megaspore tetrad tetrahedral, only one megaspore develops, megasporangium indehiscent; male gametophyte development first endo- then exosporic, tube developing from distal end of grain, to ca 2 mm from receptive surface to egg, gametes two, developing after pollination, with cell walls, with many flagellae; female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large", first cell wall of zygote transverse, embryo straight, endoscopic [suspensor +], short-minute, with morphological dormancy, white, cotyledons 2; plastid transmission maternal; two copies of LEAFY gene, PHY gene duplications [three - [BP [A/N + C/O]] - copies], nrDNA with 5.8S and 5S rDNA in separate clusters; mitochondrial nad1 intron 2 and coxIIi3 intron and trans-spliced introns present.

MAGNOLIOPHYTA

Lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, [cyanogenesis in ANITA grade?], S [syringyl] lignin units common, positive Maüle reaction [syringyl:guaiacyl ratio more than 2-2.5:1], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; origin of epidermis with no clear pattern [probably from inner layer of root cap], trichoblasts [differentiated root hair-forming cells] 0; shoot apex with tunica-corpus construction, tunica 2-layered; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides, poor in mannans; tracheid:tracheid [end wall] plates with scalariform pitting, wood parenchyma +; sieve tubes enucleate, sieve plate with pores (0.1-)0.5-10< µm across, cytoplasm with P-proteins, cytoplasm not occluding pores of sieve plate, companion cells from same mother cell that gave rise to the sieve tube; sugar transport in phloem passive; nodes unilacunar [1:?]; stomata with ends of guard cells level with pore, paracytic, outer stomatal ledges producing vestibule; leaves petiolate, lamina [formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, veins (1.7-)4.1(-5.7) mm/mm², endings free; most/all leaves with axillary buds; flowers perfect, pedicellate, polysymmetric, parts spiral [esp. the A], free, numbers unstable, development in general centripetal; P not sharply differentiated, with a single trace, outer members not enclosing the rest of the bud, often smaller than inner members; A many, filament not sharply distinguished from anther, stout, broad, with a single trace, anther introrse, tetrasporangiate, sporangia in two groups of two [dithecal], ± embedded in the filament, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally by action of hypodermal endothecium, endothecial cells elongated at right angles to long axis of anther; tapetum glandular, binucleate; microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing; pollen subspherical, tectum continuous or microperforate, ektexine columellar, endexine thin, compact, lamellate only in the apertural regions; nectary 0; G free, several, ascidiate, with postgenital occlusion by secretion, stylulus short, hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, dry [not secretory]; ovules few [?1]/carpel, marginal, anatropous, bitegmic, micropyle endostomal, outer integument 2-3 cells across, often largely subdermal in origin, inner integument 2-3 cells across, often dermal in origin, parietal tissue 1-3 cells across [crassinucellate], nucellar cap?; megasporocyte single, hypodermal, megaspore tetrad linear, functional megaspore chalazal, lacking sporopollenin and cuticle; female gametophyte four-celled [one module, nucleus of egg cell sister to one of the polar nuclei]; P deciduous in fruit; seed exotestal; pollen binucleate at dispersal, trinucleate eventually, germinating in less than 3 hours, pollination siphonogamous, tube elongated, growing at 80-600 µm/hour, with pectic outer wall, callose inner wall and callose plugs, growing between cells, penetration of ovules via micropyle [porogamous] within ca 18 hours, distance to first ovule 1.1.-2.1 mm, tube moves between nucellar cells; double fertilisation +, endosperm diploid, cellular [micropylar and chalazal domains develop diffently, first division oblique, micropylar end initially with a single large cell, divisions uniseriate, chalazal cell smaller, divisions in several planes], copious, oily and/or proteinaceous, embryo cellular ab initio, minute; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)_n]; whole genome duplication, ndhB gene 21 codons enlarged at the 5' end, single copy of LEAFY and RPB2 gene, knox genes extensively duplicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and three copies of the PHY gene, [PHYB [PHYA + PHYC]].

Evolution. Possible apomorphies for flowering plants are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear. This is because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied, there is considerable homoplasy as well as variation within and between families of the ANITA grade in particular for several of these characters, and also because details of relationships among gymnosperms will affect the level at which some of these characters are pegged. For example, if reticulate-perforate pollen is optimized to the next node on the tree (see Friis et al. 2009 for a discussion), it effectively makes the pollen morphology of the common ancestor of all angiosperms ambiguous... For other features such as details of sugar transport in the phloem, their placement on the tree is frankly speculative. Finally, for features such as parietal tissue/a nucellus only one (Nymphaeales) to three cells thick above the embryo sac and a stylar canal lacking an epidermal layer, although plesiomorphous for basal grade angiosperms (Williams 2009), I am unsure where on the tree a thicker nucellus and a stylar epidermal layer are acquired.

[NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]]: vessels +, elements with elongated scalariform perforation plates; wood fibres +; axial parenchyma diffuse or diffuse-in-aggregates; tectum reticulate-perforate [here?]; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.

MYRTALES Reichenbach  Main Tree, Synapomorphies.

Bark flaky; flavonols only, myricetin, methylated ellagic acid +; cork cambium deep seated, (polyderm +); vessel elements?; pits vestured; libriform fibres septate; tension wood +; secondary phloem stratified; internal phloem +; nodes 1:1; (spirally-thickened tracheoids +); cuticle waxes often 0; branching from current flush [all?]; leaves opposite, lamina with brochidodromous venation, (stipules +, small), colleters +; inflorescence racemose; (flowers 4-merous); hypanthium +, nectariferous; , K valvate, C clawed; A incurved in bud; pollen with pseudocolpi; G inferior, (transseptal bundles +), style +, long, minor stylar bundles +, stigma wet; ovules many/carpel, micropyle bistomal and zig-zag, inner integument ca 2 cells across; antipodal cells ephemeral; (mesotesta sclerotic), exotegmen cells tracheidal, endotesta crystalliferous; endosperm at most slight. - 9 families, 380 genera, 11027 species.

• Myrtales may be recognised by their often flaky bark; opposite leaves with colleters, at most small stipules and strong intramarginal veins; flowers with petals that are clawed or at least very narrow at the base, a more or less inferior ovary, and a usually nectariferous hypanthium. The sepals are often valvate and the stamens are usually incurved in bud.

Evolution. Divergence & Distribution. Wikström et al. (2001) dated the origin of stem Myrtales to (103-)100(-97) million years before present; the age of crown group Myrtales was estimated as (89-)85, 78(-74) million years (two penalized likelihood dates), the stem group age being (111-)106(-101) or (86-)83(-80) million years; Bayesian relaxed clock estimates for the crown group gave dates at old as 99 million years (Wang et al. 2009), while Magallón and Castillo (2009 - topology of this part of the tree uncertain) estimated ages of ca 107.9 and 108.4 million years relaxed and constrained penalized likelihood datings) for stem Myrtales. Fossils assignable to Myrtales are some 65 million years old (Crepet et al. 2004), Pigg et al. (1992) describing a fossil from the Palaeocene that they thought was close to Myrteae-Psidium, although Cretaceous pollen can be assigned to the family (Wilson 2011).

Myrtales contain ca 6% core eudicot diversity.

Plant-Animal Interactions. Lycaenidae caterpillars are quite commonly to be found on members of this order (esp. Lythraceae, Myrtaceae, Combretaceae - see Fielder 1991, 1995).

Chemistry, Morphology, etc. There are a number of other characters that are common in Myrtales and may be apomorphies for them. Raffinose and stachyose are common oligosaccharides in phloem exudate in Myrtaceae, Onagraceae, Lythraceae and Combretaceae, at least (Zimmermann & Ziegler 1975). Polyderm (alternating endodermal and parenchymatous layers laid down by a pericyclic meristem) is known from families like Onagraceae, Lythraceae, Myrtaceae, and probably Penaeaceae and Oliniaceae, at least (Mylius 1913), while in roots of some aquatic Lythraceae, Melastomataceae. Myrtaceae and Onagraceae (and Euphorbiaceae and Fabaceae) there is a distinctive lacunate cork produced from a pericyclic cork cambium (Little & Stockey 2006). Tracheoidal sclereids with spiral wall thickenings that are associated with the vein endings are known from Vochysiaceae, Lythraceae, Combretaceae, Melastomataceae, Alzateaceae and Penaeaceae (Sajo & Rudall 2002); their more general distribution needs to be checked. Since there is internal phloem, petiole and midrib bundles are often bicollateral. Weberling (2000) notes that "true rudimentary stipules" occur in Myrtaceae and most myrtalean families; stipules, when they occur, are indeed generally small, often not vascularized, and may be derived from colleters (see also Carr & Carr 1966; LaFrankie 2010). In Myrtaceae the calyx and corolla originate at about the same time, while in Lythraceae and Onagraceae the calyx is visible considerably before the corolla (Mayr 1969); it will be interesting to know the general distribution of this feature. Many Myrtales, including some Myrtaceae, have notably narrow petal bases, i.e., they are close to being clawed; the definition and distribution of clawed petals in Myrtales may have to be amended, but I have provisionally put "clawed petals" as a feature of the whole clade. Those taxa in which the stamens are straight in bud have short filaments, and the length of the style is correlated in part with the length of the hypanthial tube. Distinctive winged fruits are found in Combretaceae and rarely in Oenothera, and even more distinctive fruits that open by the placenta breaking through the ovary wall occur throughout Cuphea (Lythraceae) and in some Sonerila (Melastomataceae). The basic chromosome number for the order may be x = 12 (Graham et al. 1993).

The cork cambium is sometimes initiated in the superficial or mid-cortical position (e.g. Myrtaceae, Melastomataceae: Weiss 1890; van Tieghem 1891b).

For further information, see Mauritzon (1939a: embryology), Lourteig (1965), Venkateswarlu and Prakash Rao (1971: wood anatomy), Beusekom-Osinga and Beusekom (1975: morphology etc. around Crypteroniaceae), Johnson and Briggs (1985: morphological phylogeny), Van Vliet and Baas (1975, 1985: vegetative anatomy), Rye (1979), Solt and Wurdack (1980: chromosome number), Tobe (1989) and Tobe and Raven (1983a, 1985a, 1985b, 1987a, 1990), all embryology and ovule morphology, Dahlgren and Thorne (1985: general, and other papers in this issue of the Ann. Missouri Bot. Gard.), Boesewinkel and Venturelli (1987: ovule and seed), Weberling (1988: inflorescence morphology), Ronse Decraene & Smets (1991b: polyandry), and Almeda (1997: chromosome numbers).

Phylogeny. The position of Myrtales within the rosids was unstable in a rbcL analysis of all angiosperms (Hilu et al. 2003). However, there was some support for a position sister to all other rosids except Geraniales, Vitales and Saxifragales (Zhu et al. 2007), while Wang et al. (2009) suggested that is was sister to Geraniales, the combined group being sister to all other malvids. See also the Dilleniales and the Saxifragales pages for further discussion on the relationships of Myrtales.

Relationships within the order have been extensively studied by Conti et al. (1996, 1998, 1999, 2002), Sytsma et al. (1998, esp. 2004), Clausing and Renner (2001: Melastomataceae), Schönenberger and Conti (2001, 2003: esp. Penaeaceae area, etc.) and Wilson et al. (2005: Myrtaceae s.l.), and the tree is based on these publications. The position of Combretaceae seems still to be unclear (see also Maurin et al. 2010), although Berger and Sytsma (2010) and Soltis et al. (2011), find support (in the latter case only weak) for a position sister to [Onagraceae + Lythraceae]. Anatomy (vestured pits), some morphological features (general leaf type and insertion) and molecular data all strongly suggest that Vochysiaceae are to be included in Myrtales, but at first sight the distinctive monosymmetric spurred flowers of that family are quite unlike those of the other members of the order.

Includes Alzateaceae, Combretaceae, Crypteroniaceae, Lythraceae, Melastomataceae, Myrtaceae, Onagraceae, Penaeaceae, Vochysiaceae.

Synonymy: Melastomatineae J. Presl - Circaeales Martius, Combretales Berchtold & J. Presl, Epilobiales Martius, Henslowiales Martius, Lythrales Link, Melastomatales Berchtold & J. Presl, Memecylales Martius, Myrobalanales link, Oenotherales Bromhead, Onagrales Berchtold & J. Presl, Penaeales Lindley, Trapales J. Presl, Vochysiales Link

COMBRETACEAE R. Brown, nom. cons.   Back to Myrtales

Evergreen, trees (or shrubs); 5-desoxyflavonoids, flavonoid sulphates +; (cork epidermal); fibres with at most minutely bordered pits; sclereids +/0; petiole bundle arcuate to annular (wing bundles +); hairs unicellular, pointed, thick-walled, with a basal internal compartment, also lepidote or with stalked glands; lamina vernation conduplicate or supervolute, domatia or other glands common, stipules at most small; (plant monoecious); flowers 4-5(-8)-merous; C often small or 0; A obdiplostemonous, (= and alternate with or opposite sepals; -15), inserted below or at the hypanthial apex; G [2-5(-8)], alternate with K or odd member abaxial, unilocular, placentation apical, (nectary on top of ovary), stigma punctate (capitate); ovules (1-)2-7(-20), outer integument 3-5 cells across, inner integument 2-3 cells across, parietal tissue 8-10 cells across, nucellar cap 6-8 cells across, funicles long, usu. with obturator; fruit indehiscent, dry; seed large; endotesta tracheidal or sclerotic, ?not crystalliferous, exotegmen fibrous; embryo often green, cotyledons convolute or plicate; n = (7, 11)12-13.

14[list]/500: 3 groups below. Largely tropical. [Photo - Flower, Flower, Fruit.]

1. Strephonematoideae Engler & Diels

Imperfect tracheary elements with bordered pits; internal phloem 0; stomata paracytic; hairs appressed, 2-armed; leaves "alternate"; pollen lacking pseudocolpi, only semitectate; G half inferior; fruit largely superior; ovules 2; cotyledons hemispherical, large, conduplicate; germination hypogeal; n = ?

1/3. West Africa (map: from Jongkind 1995).

2. Combretoideae Beilschmied

(Petiole with glands); flowers often sessile; C not clawed[?]; G inferior; (embryo sac tetrasporic, 16-nucleate); fruit ± flattened and/or winged, (drupaceous); cotyledons flattened and variously folded.

13/500. Largely tropical (map: from van Steenis & van Balgooy 1966; Wickens 1976; FloraBase 2006; Stace 2010).

2a. Laguncularieae Engler & Diels

Stomata cyclocytic; lamina (with glands), revolute [Laguncularia]; bracteoles adnate to G; (C clawed); cotyledons spirally folded [convolute]; n = 13.

4/8. Tropical, often mangroves, esp. N. Australia.

2b. Combreteae Engler

(Plants lianes); included phloem +; (mucilage ducts - Terminalia); stomata anomocytic; (C small/0); (micropyle endostomal - Guiera), (parietal tissue ca 10 cells across, pachychalazal - Combretum coccineum); (integuments multiplicative); (megaspore mother cells several).

9/490. Largely tropical. Combretum (255), Terminalia (190).

Synonymy: Bucidaceae Sprengel, Myrobalanaceae Martinov, Sheadendraceae G. Bertolini, nom. invalid., Terminaliaceae Jaume Saint-Hilaire

• Combretaceae may not be very easy to recognise, although like other Myrtales they often have opposite leaves and flaking bark. Trees quite often look rather pagoda-like, branching following the Terminalia pattern, the branches often being in whorls and consisting of flattened sprays of leaf rosettes. The leaves are entire and may have pellucid dots, surface glands (also on the petiole), or domatia. The indumentum is commonly adpressed and distinctive enough under the microscope; nodes are unilacunar. The flowers are often rather small and massed in spicate inflorescences, the hypanthium can be quite long, but the corolla is small or absent. The ovary is inferior, and the single-seeded fruit is often flattened and/or winged.

Evolution. Stem Combretaceae are ca 90 million years old, with Strephonema diverging soon afterwards and diversification of the rest of the family occuring in the Tertiary (Systsma & Berger 2011). Fossils of Esgueiria, assigned to Combretaceae, have been found widely in the Northern Hemisphere in Late Cretaceous deposits ca 90-70 million years old. They seem to have inferior unilocular ovaries with apical placentation and glandular-peltate hairs (Friis et al. 1992), but there is no hypanthium, the styles are more or less separate, and the surface of the unicellular hairs of the Japanese, but not the Portugese, material is distinctly rough (Takahashi et al. 1999). The nature of the nectary is unclear; in some specimens there are structures outside the androecium that have been interpreted as possible nectaries (Takahashi et al. 1999), and this is unlike nexctaries in extant Combretaceae. The identity of these fossils should be confirmed - cf. also Hydrangeaceae? Dilcherocarpus, from the Albian-Cenomanian of the Dakota Group, Kansas, and ca 100 million years old, has recently been described and assigned to Combretaceae (Manchester & O'Leary 2010).

The flattened and/or winged fruits are often wind- or water dispersed, and Systma and Berger (2011) notes substantial dispersal of the family in the Pacific.

Chemistry, Morphology, etc. Wood fibres are usually non-septate, but those of Lythraceae, at least, are septate. The islands of included phloem in Combretum are connected in a reticulating fashion (Robert et al. 2011); den Outer and van Veenendaal (1995) noted that this system was more important in the transport of assimilates that the regular phloem outside the xylem - and that it was interesting that these plants were shrubs or trees, not lianas. Keating (1985) describes the stomata as being paracytic while Dahgren and Thorne (1985) call them anomocytic; in any event, variation in stomatal morphology is extensive (Tilney 2002).

For embryology, see Venkateswarlu (1952), for obdiplostemony, see Eckert (1966, also Tomlinson 1986). There are hairs lining the ovary loculus walls in Combretum.

Some information is taken from Fagerling (1941a: embryology of Quisqualis), Graham (1964: general), Verhoeven and van der Schijff (1974: anatomy, including root cork cambium!), Venkateswarlu and Prakash Rao (1971) and Jongkind (1995), both Strephonema, El Ghazali et al. (1998: pollen) and Stace (2006: general; 2010: general, revision of New World taxa).

Phylogeny. Strephonema may be sister to the rest of the family. Lumnitzera and Laguncularia, both mangrove plants, are sister taxa, but Conocarpus, also found in similar habitats, is not immediately related (Tan et al. 2002; Maurin et al. 2010). Maurin et al. (2010) in particular discuss details of relationships within the family, especially in the large genera Terminalia and Combretum.

Classification. For generic limits, especially around Combretum, see Stace (2007), while Maurin et al. (2010) suggest that the limits of Terminalia, currently paraphyletic, be expanded; support values underpinning change in neither case is currently very high.

[[Onagraceae + Lythraceae] [[Vochysiaceae + Myrtaceae] [Melastomataceae [Crypteroniaceae [Alzataeaceae [Rhynchocalycaceae [Penaeaceae + Oliniaceae]]]]]]: ?

[Onagraceae + Lythraceae]: tannins often not abundant, soluble oxalate accumulating; vessels in groups in the wood; fibres with at most minutely bordered pits; petiole bundle arcuate; (flowers vertically monosymmetric); (pollen at anthesis with starch); nucellus with starch grains, hypostase +; megaspore mother cells several; K persistent; exotegmen fibrous; starch grains in nucellus; x = 8.

Evolution. Divergence & Distribution. The stem of this clade has been dated to end Albian ca 100 million years ago, divergence of the two families at end-Cenomanian at ca 94 million years ago, both Cretaceous (Sytsma et al. 2004).

Chemistry, Morphology, etc. Both Trapa and some species of Ludwigia are aquatics with distinctive floating rosettes of expanded leaves. Decodon is the only typically pentamerous genus in Lythraceae (Graham 2006); see also Ludwigia (Onagraceae) - both seem to be sister to the rest of their respective families! Hence working out where floral merism changes on the tree becomes difficult. A number of Lythraceae, including Trapa, have capitate stigmas, and this could be another feature uniting the two families.

ONAGRACEAE Jussieu, nom. cons.   Back to Myrtales

Plants herbaceous; flavonoid sulphates +; raphides +; (leaves spiral), lamina vernation ± flat to involute, margins toothed, stipules 0); inflorescence raceme or spike (flowers axillary), bracteoles often 0, C deciduous, (not clawed); A straight, anthers polythecate; pollen with viscin threads, starchy, (colpate), apertures protruding, ektexine paracrystalline, beaded; ovary alternating with K, (placentation parietal), stigma capitate; ovules with outer integument 2-5 cells across, inner integument 2(-3) cells across, parietal tissue ca 2(?-13 - Vesque) cells across, nucellar cap ca 2 cells across; embryo sac monosporic, micropylar megaspore functional, 4-nucleate [Oenothera type]; fruit a capsule opening loculicidally down the sides; exotesta often hairy or papillate, inner walls thickened and lignified (mesotestal cells thickened, ± sclerotic; endotegmic cells longitudinally elongated, "tanniniferous", inner walls thickened); endosperm nuclear, diploid.

22[list]/656 - two subfamilies below. World-wide (map: based on Raven 1963, 1967; Meusel et al. 1978, P. Hoch & W. Wagner, pers. comm.).

1. Jussiaeoideae Beilschmied

Flowers 4-5-merous; hypanthium 0; (A 10); pollen in tetrads (monads; large irregular clumps); G with central vascular bundles, style short; nectary on top of ovary; parietal tissue 3-6 cells across, hypostase +; megasporocyte 1.

1/82: World-wide, esp. America. [Photo - Flower.]

2. Onagroideae Beilschmied

(Plant woody - esp. Fuchsia], ncluded phloem +; flowers 4-merous (2-merous - Circaea), hypanthium long, deciduous; (A also 1, 2); transseptal vasular bundles +, (style short), no minor stylar bundles (stigma 4-lobed; dry); (ovules wth parietal tissue 10-25 cells across); (fruit baccate), K not persistent; n = 5+.

21/574: Epilobium (165), Oenothera (145: inc. Gaura, etc.), Fuchsia (105), Clarkia (42), Lopezia (22). World-wide, but esp. western North America. [Photo - Flower, Flower.]

• Onagraceae are herbs to shrubs that are recognisable by their usually opposite and quite often toothed leaves with small stipules and the often 4-merous flowers with an inferior ovary and a well-developed floral tube. The calyx is usually rather thin, reflexed, and deciduous, there are up to eight stamens, and the pollen has viscin threads, so it is conspicuously clumped.

Evolution. Divergence & Distribution. The age of stem-Onagraceae is end-Cenomanian, ca 94 million years ago (Sytsma et al. 2004).

In the translocation hybrid system in Oenothera (see below) genome and plastome may be incompatible, and the resultant inviability of some genome/plastome combinations may provide genetic barriers (Stubbe & Steiner 1999). Although these permanent translocation hybrids self, they show an increased diversification rate over sexual species, interestingly, there are frequent reversals from the hybrid state to sexuality (Johnson et al. 2011).

Plant-Animal Interactions. Some caterpillars are found both on Vitaceae and Onagraceae (Forbes 1956) - and both contain raphides. Different rusts occur on Onagroideae and Jussiaeaoideae (Savile 1979b).

Floral Biology. For details of floral morphology in Onagraceae and its relation to pollination, see Wagner et al. (2007). Pollination in North American members of the family has been studied in great detail (e.g. references in Linsley et al. 1973; Clinebell et al. 2004).

Genes & Genomes. All the chromosomes in some species of Oenothera form a ring, a series of permanent translocations having occured, and the whole genome forms a single linkage unit (Cleland 1972). There is paternal transmission of chloroplasts. Particular combinations of genome and plastome may be incompatible, the whole system may break down, etc. (see Harte 1993: the contributions of Oenothera to biology; Stubbe & Steiner 1999 and references: translocation, etc; Wagner et al. 2007).

Chemistry, Morphology, etc. The stipules of Ludwigia can be quite prominent. There are some very distinctive floral morphologies in Onagroideae. Thus Circaea has only two petals and two stamens, the latter being opposite the sepals. In the monosymmetric flowers of Lopezia there is only a single extrorse anther, a petaloid staminode, while the two adaxial petals may be recurved, with pseudonectaries on their claws. Gongylocarpus has sessile flowers, as is quite common in Onagraceae, but after pollination the ovary becomes completely enveloped by stem tissue. The viscin threads that characterize the family vary considerably in morphology, often being annular-vermiform, but they are also smooth or irregularly beaded (Skvarla et al. 1976). The style of Ludwigia has minor bundles, but these are absent in other members of the family. in Oenothera, spores from the same megaspore mother cell may germinate and - presumably - compete (Noher de Halac & Harte 1977). x = 10, 11, 15 in the basal clades of Onagroideae, ?18 in Epilobeae, and 7 in Onagreae (Wagner et al. 2007).

For other information, see Johansen (1928: hypostase presence, and correlation with the environment), Eyde (1982: floral anatomy), Maheshwari (1947), Tobe and Raven (1986a, b, 1987c, 1996) and Hoch et al. (1993: variation in anther septa development, embryology), Tobe et al. (1987: seed coat anatomy), the Onagraceae website (general) and Wagner et al. (2007: superb summary).

Phylogeny. Within Ludwigia, taxa with five and those with ten stamens form separate clades (Barber et al. 2008). Knowledge of relationships along the backbone of the Onagroideae seems to be stabilising. Hauya, [Fuchsia + Circaea], Lopezia, and Gongylocarpus are successive branches (= tribes) along the tree leading to [Epilobeae + Onagreae] (Levin et al. 2003, 2004), however, Ford and Gottlieb (2007) obtained a grouping [Hauya [Fuchsia + Circaea]] that was sister to other Onagroideae.

Classification. Reflecting the new, but for the most part well supported phylogeny of the family, taxon limits have had to be adjusted, so Oenothera has been expanded and Camissonia very much cut up (e.g. Levin et al. 2004); for appropriate nomenclatural changes, see Hoch and Wagner (2007). The Onagraceae website contains a largely up-to-date summary of classification, etc., while Wagner et al. (2007) enumerate all supraspecific taxa.

Botanical Trivia. In 1827 Robert Brown recorded the phenomenon that is now called Brownian motion when observing the pollen grains of Clarkia pulchella.

Hugo de Vries thought that the abrupt appearance of O. lamarckiana was an example of normal evolution, which for him was a process in which mutation = major change/speciation, natural selection not being involved. However, it turned out that O. lamarckiana was a morphological variant that had occurred because of the breakdown of the permanent translocation system mentioned above (cf. Linnaeus and Peloria [= Linaria, Plantaginaceae]).

Synonymy: Circaeaceae Berchtold & J. Presl, Epilobiaceae Ventenat, Fuchsiaceae Lilja, Isnardiaceae Martinov, Jussiaeaceae Martinov, Lopeziaceae Lilja, Oenotheraceae C. C. Robin

LYTHRACEAE Jaume Saint-Hilaire, nom. cons.   Back to Myrtales

Herbs to trees; quinolizidine alkaloids +; mucilage cells common; hairs uni- or bi(multi)cellular; leaves (spiral), lamina vernation flat to conduplicate, (margins dentate - Trapa), stipules +/0; (inflorescence determinate); flowers (3) 4 (5) 6(-16)-merous, heterostyly common; hypanthium/K often strongly ribbed, with alternating appendages, (hypanthium spurred), (0, but with K + C tube), C crumpled in bud, (0); A basically obdiplostemonous, (1 - = and opposite sepals - many, centrifugal or centripetal), inserted just below C to near ovary, filaments of unequal length; (pollen pseudocolpi 0), (surface striate); (nectary at base of G); G [2-6(-many)], superior to inferior, orientation variable, (placentation parietal), stigma capitate to punctate, also dry; ovules (1-few/carpel), outer integument 2-7(-9) cells across, inner integument 2(-3) cells across, parietal tissue ca 7 cells across, "chalazal strand" +, (postament +); fruit a capsule, dehiscence various, inc. circumscissile, (indehiscent; berry), K often ± enclosing fruit; seeds flattened; testa multiplicative, many-layered (not Duabanga), exotesta various, (invaginated mucilage hairs +), endotestal cells often elongated and tracheidal/sclerotic, (crystalliferous), (endotegmen of crossing fibres); (cotyledons folded); n = (5-)8(-11, + polyploids), chromosomes 1-4 µm long.

31[list]/620: Cuphea (250), Diplusodon (75), Lagerstroemia (55 - A centrifugal), Nesaea (55 - probably to include Ammannia - then = 80), Rotala (45), Lythrum (36). Tropical, but some temperate (map: from van Balgooy 1975; Graham et al. 2005). [Photo - Flower]

• Lythraceae are herbs to trees that are recognisable by their flaky bark, opposite, entire leaves that lack gland dots, flowers with a ribbed hypanthium or K + C tube, a rather thick, valvate calyx, clawed petals that are crumpled in bud, and often 10 or more stamens of unequal lengths. The ovary is more or less superior, and the fruit is usually a capsule; the testa of about half the genera has distinctive, initially inverted mucilaginous hairs.

Evolution. Divergence & Distribution. The age of stem-Lythraceae may be end-Cenomanian, ca 94 million years ago (Sytsma et al. 2004). Recent fossil data are consistent with this. Pollen from Montana from the Lower Campanian 82-81 million years ago has reliably been identified as Lythrum, and also its segregate, Peplis; somewhat younger (72-78 million years) fossil pollen is known from Siberia (Grímsson et al. 2011: exquisite micrographs). The fossil Trapago is known from deposits 73-65 million years before present, and other fossils assignable to Myrtales are perhaps slightly older (Crepet et al. 2004, for references). Sonneratia, a mangrove genus, has a long fossil record (its distinctive pollen is called Florschuetzia - Muller 1978); for the evolution of the mangrove habitat, see Rhizophoraceae. Decodon, now restricted to east North American, was widely distributed in the North Hemisphere from the Eocene onwards (Ferguson et al. 1997 and references; Little et al. 2004).

Seed Dispersal. Taxa whose seeds have mucilaginous hairs are more or less myxospermous. The fruits of Cuphea open by the placenta expanding and moving laterally, breaking through both the thin ovary wall and the hypanthium; the seeds are exposed on the placenta.

Genes & Genomes. Graham and Cavalcanti (2001) suggest that x = 8 is the basic chromosome number for the family.

Chemistry, Morphology, etc. Quite strongly monosymmetric flowers are found in some species of Cuphea, e.g. C. glutinosa. Androecial development is both centrifugal and centripetal (Weberling 1989 and references; Ronse Decraene & Smets 1991). Pollen is notably variable (Graham 2006). The stamens may be borne on one side of the flower (also in some Onagraceae) and so resulting in rather weakly monosymmetric flower - this is much more marked in Melastomataceae. Species of the large genus Cuphea consistently have eleven stamens. When G = K, the carpels may alternate with or be opposite to them, when G = 2, the carpels may be transverse or median, when G = 3, the odd carpel is adaxial (Eichler 1878; Baillon 1877; Spichiger et al. 2002).

The inferior ovary of Punica granatum is unique in flowering plants, appearing to have two (or three) superposed layers of carpels, the basal with axile and the others with intrusive parietal placentation; the placentation is fundamentally axile, the appearance of parietal placentation being the result of growth at the base of the ovary (Sinha & Joshi 1959 for vasculature; Leins 1988 for androecial development). In the other species of the genus, P. proto-punica, there is a more ordinary semi-inferior ovary.

For general information, see Graham (2006); for embryology of Trapa, see Ram (1956), for seed anatomy, see Grütter (1893), for some vegetative anatomy, see Little et al. (2004).

Phylogeny. S. Graham et al. (2005) found some support for the topology [Decodon [[Lythrum + Peplis] remainder of the family]]; these other genera were included in two large clades, inverted mucilaginous hairs in the testa possibly being a synapomorphy. However, support along the whole back-bone was weak, and in some analyses there were two major clades in the whole family, with the three genera just mentioned forming a subclade within one of them. S. Graham et al. (2005) list characters for the major clades that they found. The old Sonneratiaceae - Sonneratia plus Duabanga - are not monophyletic (Shi et al. 2000; see also Huang & Shi 2002: one species per genus sampled); Sonneratia itself may be sister to Trapa. Rotala and Ammannia, previously thought to be close, are well separated, and relationships within the former genus have been clarified (Graham et al. 2011). For a phylogeny of Cuphea, see Graham et al. (2006).

Some taxa with particularly distinctive morphologies:

• Punica: ellagitannins in the fruit; xylem parenchyma 0; cuticle waxes as platelets; C clawed, crumpled in bud; G on two or three levels (see above), transseptal bundles +, micropyle exostomal, although bistomal according to Corner (1976); exotestal cells columnar, fleshy, tegmen undistinguished; n = 7, 8; its alkaloids are like those of other Lythraceae.

• Sonneratiaceae: mangrove plants; xylem parenchyma 0; branched sclereids +; tegmen not persistent; embryo green; n = 12.

• Trapa: floating aquatic herbs, submerged leaves fimbriate; flowers 4-merous; tapetal cells multinucleate; G {2], transverse, placentation apical, style hollow; ovule one/carpel, nucellar beak massive; fruit indehiscent, sepals persist as horns; testa multiplicative; endosperm starchy, embryo with massive haustorial suspensor, cotyledons very unequal; n = 20, 24.

Classification. For likely changes in generic limits around Ammannia, see Graham et al. (2010, esp. 2011).

Previous Relationships. Some morphologically distinctive taxa until recently separated as their own families - Trapaceae (water chestnut), Sonneratiaceae, Punicaceae (pomegranate) - nestle firmly within Lythraceae.

Synonymy: Ammanniaceae Horaninow, Blattiaceae Engler, Duabangaceae Takhtajan, Lagerstroemiaceae J. Agardh, Lawsoniaceae J. Agardh, Punicaceae Berchtold & J. Presl, nom. cons., Sonneratiaceae Engler, nom. cons., Trapaceae Dumortier

[[Vochysiaceae + Myrtaceae] [Melastomataceae [Crypteroniaceae [Alzataeaceae [Rhynchocalycaceae [Penaeaceae + Oliniaceae]]]]]]: inflorescences with at least branches cymose.

Chemistry, Morphology, etc. Oil glands are found in the anthers of many Myrtaceae, and a number of other taxa in the Melastomataceae-Crypteroniaceae clade also have a very much expanded connective. Whether some staminal features - perhaps linked with pollination - are a higher-level apomorphy in this clade awaits further study.

[Vochysiaceae + Myrtaceae]: hairs simple, 1-2-celled; K and C imbricate; pollen syncolporate; style depressed in apex of gynoecium; fruit a capsule.

Evolution. Divergence & Distribution. Sytsma et al. (2004) discuss the age and biogeographic history of the whole group in some detail.

Phylogeny. Conti et al. (1996) found a well supported [Heteropyxidaceae + Psiloxylaceae] sister to [Myrtaceae + Vochysiaceae]; note, however, that the pollen grains of the first two are similar to those of Myrtaceae (Dahlgren & Thorne 1985). Monophyly of Myrtaceae s. str. (= Myrtoideae) was not strong (Conti et al. 1996, 1998). However, Wilson et al. (2005: matK only) found Myrtaceae s. str. to have 80% jacknife support, while Myrtaceae s. str. + [Heteropyxidaceae + Psiloxylaceae] (all together = Myrtaceae here) had ³95% support; a similar set of relationships were found by Sytsma et al. (2004; matK and ndhF).

VOCHYSIACEAE A. Saint-Hilaire, nom. cons.   Back to Myrtales

Trees (lianes); 5-deoxyflavonoids +; plants Al-accumulators; included phloem +; leaf traces run along stem before entering petiole; pericyclic fibres at most few; sclerified bundles + (0) (secretory canals +) in pith; sclereids, mucilage cells +; cuticle waxes as ± grouped parallel platelets; stomata also paracytic; indumentum often brown, hairs T-shaped, unicellular, or stellate; leaves opposite, leathery, lamina vernation conduplicate, (venation eucamptodromous - Callisthene), stipules cauline, (with associated large glands), sometimes colleter-like; inflorescence terminal (axillary), with lateral cincinni; flowers strongly obliquely mono- or asymmetric; hypanthium 0, K basally connate, one adaxial-lateral larger and with nectariferous spur from floral axis, (three K petaloid - Korupodendron), C 1, 5 (3), unequal; A 1, straight, more or less opposite abaxial lateral petal, (staminodes 2); G [3 (4)], odd member adaxial, stigma punctate to subcapitate; ovules with outer integument 2-3 cells across, inner integument ca 2 cells across; fruit samaroid [by 4 or 5 accrescent K lobes], or loculicidal capsules; seeds variously winged, testa thin, mesotesta ?not sclerotic, endotestal cells ± thickened, pectic, mesotegmic cells fibrous, thick-walled or not, or testa multiplicative, exotesta with thickened hairs, a few other layers persisting, but rest and tegmen disorganised; cotyledons folded; n = 11, 12.

7[list]/190: Vochysia (100), Qualea (60). Lowland tropical America, apart from Erismadelphus and Korupodendron from W. Africa (map: from Stafleu 1954). [Photo - Flower.]

• Vochysiaceae are readily recognisable by the combination of a rather ordinary Myrtalean vegetative body, i.e. their leaves are opposite, entire, and with lateral veins looping and joining near the lamina margin, with their rather large and distinctive monosymmetric or asymmetric flowers with a spurred calyx that sometimes forms a spiral, and a single stamen with a long anther and short filament. Some taxa have large, flat, stipular glands.

Evolution. Divergence & Distribution. The present distribution of Vochysiaceae on either side of the Atlantic is likely to be the result of dispersal (Sytsma et al. 2004).

Chemistry, Morphology, etc. Leaves of small saplings may have short petioles and swollen leaf bases. At least in Vochysia guatemalensis there are conspicuous, symmetrically-arranged mucilage canals in the pith. The stamen may be opposite either the abaxial-lateral C or the adjacent K; in the latter case, it is off the plane of symmetry (Kawasaki 1998; also Litt & Stevenson 2003b). The flowers are basically epigynous, the ovary being initiated in an inferior position; the superior position in the mature flower is secondary (Litt 1999; Litt & Stevenson 2003a). Baillon (18) suggested that the odd carpel is abaxial, while Corner (1976) described the ovules of Qualea sp. as being long-exostomal.

For anatomy, see Sajo and Rudall (2002), for floral development and morphology, see Litt and Stevenson (2003a, b), for a general account, see Kawasaki (2006).

Phylogeny. Erismieae, containing the tropical American Erisma and the West African Erismadelphus and Korupodendron, are monophyletic. They have cortical/subepidermal phellogen; G 1, ± inferior (perhaps plesiomorphic), 1-2 lateral to apical ovules/carpel; fruit samaroid, with persistent enlarged K; testa undifferentiated, with vascular bundles. Vochysieae are probably not monophyletic (Litt 1999).

Previous Relationships. Because of their monosymmetric, spurred flowers Vochysiaceae were often associated with families that are no longer thought to be at all closely related. Thus Vochysiaceae, often including Euphronia (e.g. Mabberley 1997; Takhtajan 1997: see Malpighiales-Euphroniaceae here), were placed in Celastrales by Cronquist (1981), and in Vochysiales, along with families like Malpighiaceae (in Malpighiales), Tremandraceae (= Elaeocarpaceae, in Oxalidales) and Krameriaceae (in Zygophyllales), by Takhtajan (1997).

MYRTACEAE Jussieu, nom. cons.   Back to Myrtales

Ethereal oils [usu. terpenes] +; wood fibres with distinctly bordered pits; leaves with gland dots; apex of connective glandular [terpene-producing].

131/4620, three groups below. Worldwide, mostly tropical-warm temperate.

1. Psiloxyloideae Schmid

Plant "tanniniferous"; leaves spiral; plant dioecious; A erect in bud, each with separate traces; staminate flowers: anther sacs each opening separately; pistillode +; carpellate flowers: staminodia +; G [3]; embryo sac bisporic, 8-nucleate [Allium type]; endotesta crystalliferous, cells periclinally elongated; x = 12.

Chemistry, Morphology, etc. Johnson and Briggs (1984) emphasized the fully superior nature of the ovary in Psiloxyloideae (= their Psiloxylaceae), with its relatively narrow base, comparing it with the more or less inferior ovary of Myrtoideae (Myrtaceae), which always had a broad base.

2/4. Southern Africa, Mascarenes.

1A. Heteropyxideae Harvey

Trees; no axial xylem parenchyma; epidermal wax crystalloids as small platelets; leaves with domatia, stipules minute; (plant monoecious); staminate flowers: stamens = and opposite petals (+ 1-3 opposite sepals); carpellate flowers: (G also [2]), stigma capitate; ovules hemitropous; seeds with 2 wings at either end, exotesta with tangentially elongated cells, walls scalariform-reticulately thickened, exotegmic cells elongated.

1/3. Central and S.E. Africa.

Synonymy: Heteropyxidaceae Engler & Gilg, nom. cons.

1B. Psiloxyleae (Croizat) A. J. Scott   Back to Myrtales

Trees; secretory canals in the young stem; vestured pits?; fibres septate, crystalliferous; nodes ?; glands not producing ethereal oils; hairs 0; stipules colleter-like; (plant polygamodioecious), pedicels articulated; flowers 4-5(-6)-merous; C coriaceous, caducous, punctate, staminate flowers: A 2x C, anthers versatile; carpellate flowers: (G also [4]), style 0, stigma large, lobed; ovules hemicampylotropous; fruit baccate, punctate; exotesta cells large, exotegmen crushed.

1/1: Psiloxylum mauritianum. Mascarenes.

Evolution. Sytsma et al. (2004) suggest that Psiloxylon may have been hopping about on islands in the Indian Ocean for almost 40 million years.

Synonymy: Psiloxylaceae Croizat

2. Myrtoideae Sweet

(Ectomycorrhizal) trees and shrubs; terpenes diverse and abundant; (plants Al accumulators); (cork cambium superficial); sieve tubes with non-dispersive protein bodies; (stomata paracytic); (hairs multicellular); leaves opposite or spiral, lamina vernation variable, (2ndary veins palmate), stipules 2, or several, colleter-like, or 0; flowers (3-)4-5(-8)-merous; (K or P calyptrate, circumscissile), C (0-)4-5(-12), often deciduous, ± clawed; A many, conspicuous, (5, opposite C, 10), in fascicles opposite C (K), in ring, development centripetal to centrifugal; pollen often syncolpate, G [2(-18], at least partly inferior, alternate or opposite petals or odd member abaxial, placentae well-developed, (1-locular, placentation basal), transseptal bundles +, minor stylar bundles 0, stigma punctate to capitate (peltate), also dry; ovules (1-15/carpel), (unitegmic), outer integument 2-6(-12) cells across, inner integument 2(-4) cells across, parietal tissue 2-12 cells across, nucellar cap 0, hypostase 0, (obturator +); (fruit baccate); exotesta variously thickened, endotesta thickened or not, (sclerotic palisade cells at the micropyle), (testa multiplicative, ± sclerotic [e.g. Psidium, Myrtus]), (exotegmen 0); embryo (± undifferentiated, hypocotylar - Eugenia), green or white, straight or curved, cotyledons often connate, accumbent or incumbent, intricately folded, etc.; n = (5-)11(12).

129[list]/5330: Eugenia (1115, to include Hexachlamys), Syzygium (1045), Eucalyptus (800), Myrcia (400-750: limits unclear), Melaleuca (220), Corymbia (115), Verticordia (100), Calyptranthes (100: limits unclear), Psidium (100), Campomanesia (80), Leptospermum (80), Calytrix (75), Kunzea (60), Myrcianthes (50), Metrosideros (50: limits unclear), Darwinia (45), Xanthostemon (45), Tristania (40). Tropical, also temperate, esp in Australia (map: from Meusel et al. 1978). [Photo - Bark, Flower, Flower, Fruit.]

Synonymy: Baeckeaaceae Berchtold & J. Presl, Chamelauciaceae Rudophi, Eugeniaceae Berchtold & J. Presl, Kaniaceae Nakai, Leptospermaceae Berchtold & J. Presl, Melaleucaceae Vest, Myrrhiniaceae Arnott

• Myrtaceae are often aromatic plants recognisable by their flaky bark, their entire, punctate leaves, and their imbricate calyx, often rather fugaceous corolla, and androecium with numerous conspicuous stamens each often with an apical gland. In fact, in leaf, flower and fruit there is considerable variation. Many taxa have opposite leaves with a well-developed intramarginal vein; there is a group of genera with spiral leaves that dry a distinctive, dark, almost purplish color. Many genera have inferior ovaries and baccate fruits, while another large group of genera has ± superior ovaries and capsules.

Evolution. Divergence & Distribution. For a summary of fossils attributed to Myrtaceae, and of ages for various clades in the family, see Biffin et al. (2010a), who suggest an age for crown Myrtaceae of 87-85 million years (see also Sytsma et al. 2004). Wilson (2011) suggested largely similar ages, the pollen record suggesting the existence of at least some tribes in the late Cretaceous, but he also emphasized the increasing aridity of the Oligocene-Miocene as leading to the rapid divergence of major clades in the famil (for fossils, see also Basinger et al. 2007).

An estimate for the age of Eucalyptus s.l. is Late Cretaceous-Palaeocene (Ladiges et al. 2011). Fossils identified as Eucalyptus, possibly of the relatively widespread subgenus Symphyomyrtus, have recently been found in Argentinian Patagonia in early Eocene deposits of ca 51.9 million years old (Wilf et al. 2010; esp. Gandolfo et al. 2011). Ladiges et al. (2011) suggest that within two clades of Eucalyptus s.l. there was independent adaptation to arid/semi arid conditions.

Bacterial/Fungal Associations. Dry-fruited Myrtoideae are ectomycorrhizal (e.g. Smith & Read 1997; see also Moyersoen et al. 2001) and are especially abundant in Australia.

Ecology. Eucalyptus s.l. in particular dominates over 90% of the woodlands and forests there (Lawler & Foley 2002). Most species of Eucalyptus s.l. have epicormic strands in their bark in which there are meristem strands up to 10 mm long, although there are not often organised buds; this helps explain the resprouting of many Eucalyptus species (but not E. regnans, the snow gum) after even quite severe fires (Burrows 2002).

Plant-Animal Interactions. Myrtoideae are noted for the amount and diversity of the terpenes that they produce (Keszei et al. 2010), and it has been suggested that these compounds may be involved in defence against herbivores (Lawler & Foley 2002). However, they seem rather to be signalling compounds, and it is a variety of formylated phloroglucinol compounds, for the most part biosynthetically unrelated to terpenes, that are actually involved in deterrence (Moore et al. 2004).

Tortricine moths (Epitymbiini) larvae feed on Myrtaceae leaf litter in Australia, and some other moth groups are also foliovores on this family there (Powell et al. 1999). About half the galls on Australian plants have been recorded from Myrtaceae (Mani 1964). Thus Eriococcidae (scale insects) are widely distributed on Eucalyptus and other members of the family (Gullan et al. 2005), while galls in this genus are also commonly formed in a three-way mutualistic association of a nematode Fergusobia (the actual gall-former) and the dipteran Fergusonina, which the nematode parasitises for part of its life cycle (Taylor et al. 2005; Ye et al. 2007).

Floral Biology & Seed Dispersal. The floral diversity of Myrtaceae in Australia is striking. In many Myrtaceae the numerous stamens with their brightly coloured filaments are the part of the flower than attracts pollinators visually, and in a number of taxa such as Callistemon, the bottle-brush, the flowers are aggregated into inflorescences all the flowers of which open simultaneously. Calothamnus has monosymmetric flowers, the upper "lip" being formed by a flattened structure, the filaments of all the stamens which are fused and form a single unit (Westerkamp & Claßen-Bockhoff 2007), while Verticordia has elaborately-fringed sepals; androecial development shos much variation (e.g. Orlovich et al. 1999 and references). The anther glands (see e.g. Landrum & Bonilla 1996) produce oils, sometimes perhaps to attract pollinators, but also to help in the attachment of pollen to stylar hairs that are involved in the secondary pollen presentation that occurs in Verticordia and a number of other Australian members of the family (Howell et al. 1993; Ladd et al. 1999). Most Syzygium and Myrteae are bee-pollinated (Biffin et al. 2010a).

It is not surprising that testa anatomy correlates with fruit type: capsular fruits have exotestal seeds; baccate fruits have seeds with a generally sclerotic testa. The shift to fleshy fruits in Syzygieae and Myrteae seems to have been accompanied by increased diversification rates (Biffin et al. 2010a).

Economic Importance. For Eucalyptus s.l., now widely grown for its timber and essential oils, see Coppen (2002).

Chemistry, Morphology, etc. For polyhydroxyalkaloid distribution (pyrrolizidine, pyrrolidine, and piperidine alkaloids), see Porter et al. (2000); they occur in Psiloxylon and some groups of Myrtoideae. A number of Myrtoideae produce gums, and especially terpenes (Keszei et al. 2010), while some have high silica content in their leaves (Westbrook et al. 2009).

Perianth parts of some Eucalyptus relatives may be undifferentiated and/or variously fused (e.g. Drinnan & Ladiges 1989a, b; Bohte & Drinnan 2005); circumscissile abscission of the hypanthium occurs in various ways. Androecial variation is extreme, even in quite closely-related taxa; even when the stamens are apparently oppositisepalous, this condition is developmentally derived from an oppositipetalous androecium (see e.g. Carrucan & Drinnan 2000; Drinnan & Carrucan 2005; see also Orlovich et al. 1999 and references for floral development). There is considerable variation in ovule morphology (Bohte & Drinnan 2005), and the parietal tissue varies greatly in thickness (very thick in Eugenia - see van Wyk & Botha 1984); Corner (1976) described the micropyle as being exostomal; it is variable, but perhaps most commonly bistomal.

Seed coat (see also ovule) and embryo vary greatly, e.g. van Wyk and Botha (1984). Myrtaceae quite commonly have a more or less elaborated basal portion of the hypocotyl bearing root hairs, however, in Angophora there is a broad, disc-like structure apparently devoid of such hairs (Baranov 1957).

For the phytochemistry of Heteropyxis, see Mohammed et al. (2009); the plant apparently lacks terpenes.. Heteropyxideae are perhaps most similar to Myrtoideae-Leptospermeae; both wood anatomy (e.g. bordered pits) and pollen are like those of Myrtoideae (Stern & Brizicky 1958). The stamens have separate traces and the androecium shows no signs of being fasciated.

For ideas on the inflorescence structure of Myrtoideae, see Briggs and Johnson (1979). For general information on the family, see Schmid (1980) and especially Wilson (2011), for information on the very large genus Syzygium s.l., see Parnell et al. (2007) and Soh and Parnell (2011: leaf anatomy), for Eucalyptus, see McKinnon et al. (2008), for Eugenia, see van Wyk and Botha (1984: seed coat, etc.) and van Wyk et al. (1980: cork cambium initiation) and other papers by van Wyk and collaborators, for terpenes in Australian Myrtaceae, see Keszei et al. (2008), and for lamina anatomy of Brazilian Myrtoideae, see Cardoso et al. (2009).

Phylogeny. Wilson et al. (2005) provide a matK phylogeny and Biffin et al. (2007) an ITS phylogeny. The limits of major clades (tribes) are similar in these two studies, but the relationships between the clades are less so, although they are poorly supported. Fleshy-fruited Myrtoideae (the old Myrtoideae s. str. - see below) are largely derived and monophyletic, although the large genus Syzygium s.l. represents an independant acquisition of the fleshy fruit from that in Eugenia itself and the bulk of Myrteae (see also Johnson & Briggs 1984); for relationships in these plants, see also Biffin et al. (2010a). For relationshipsin Myrceugenia, see Murillo-A. et al. (2012). The fleshy-fruited Myrcia is strongly paraphyletic (Lucas et al. 2011). The capsular-fruited Myrtoideae are paraphyletic (Sytsma et al. 1998; Wilson et al. 2001; Salywon et al. 2002).

Phylogenetic relationships around the Australian Eucalyptus s.l. are discussed by Parra-O. et al. (2009), Steane et al. (2011), and references. Although Melaleuceae, another predominantly Australian group, are strongly supported as being monophyletic, the three main clades that make it up have high posterior probabilities but only moderate to low bootstrap support; most of the small genera previously recognised in this tribe fall into a single one of these clades, along with a group of species of Melaleuca s. str. (Edwards et al. 2010; see also Brown et al. 2001). See van der Merwe (2005) for relationships in Eugenia, mostly African, and de Lange et al. (2010) for a phylogeny of the Antipodean Kunzea.

Classification. Myrtaceae s. str. (excluding Psiloxyloideae) were traditionally divided into Leptospermoideae - leaves spiral to opposite; fruit dry, dehiscent - and Myrtoideae - polyhydroxyalkaloids common; leaves opposite; terpenoid-containing glands in the apex of the connective, stigma dry; fruit fleshy, indehiscent. This distinction is untenable (see above). For a classification of Myrtoideae in which 15 tribes are recognized, see Wilson et al. (2005) and Wilson (2011)

The large genus Syzygium in the past has sometimes been synonymised under Eugenia, along with Acmena and other segregate genera, although the two are not immediately related (see Schmid 1972 for a pre-molecular resolution of the problem). Some generic limits in Myrteae are problematic (Lucas et al. 2005, 2007), and generic limits of and infrageneric groupings within Myrcia need attention (Lucas et al. 2011). Biffin et al. (2006; see also Biffin et al. 2007; Biffin & Craven 2011) suggest that Syzygium should be delimited broadly, at least pending a better understanding of the morphological variation of this clade. Eucalyptus may be in the process of being dismembered (Parra-O. et al. 2009 and references). On the other hand, the limits of Melalauca are being expanded; if genera were segregated they would both be small and undiagnosable, distinctive characters being highly homoplastic in the group (Edwards et al. 2010). The limits of Neotropical Eugenia also seem best expanded (Mazune Capelo et al. 2011 for a summary). In general, generic limits seem rather unclear (see also Wilson 2011).

Govaerts et al. (2008) provide a world checklist of Myrtaceae.

Botanical Trivia. Eucalyptus regnans, the snow gum, is the tallest angiosperm, although in mass much less than Sequoia or Sequoiadendron (Cupressaceae). It may grow up to 101 m (ca 330 feet) tall, however, before the logging of the last century and a half there may have been very much taller individuals substantially over 400 feet (Carder 1995).

Thanks. I am grateful to Z. Rogers for discussion about Heteropyxis.

[Melastomataceae [Crypteroniaceae [Alzataeaceae + Penaeaceae]]]: (plants Al accumulators); (nodes swollen); branched or unbranched sclereids +/0 within same family; C clawed?; connective abaxially much expanded; endothecial thickening absent/atypical; nectary 0.

Evolution. Divergence & Distribution. Separation of the two lineages in this clade occured about 80 million years ago (Renner et al.

Chemistry, Morphology, etc. A number of taxa, but apparently not Melastomataceae, have more than a single branch from the leaf axil. Nodes other than simple unilacunar are quite widespread, however, a survey of nodal anatomy, particularly that of Melastomataceae, is much needed. The connective is least expanded in Penaeaceae - Rhynchocalyx.

Phylogeny. For relationships in this area, see Conti et al. (2002).

MELASTOMATACEAE Jussieu, nom. cons.   Back to Myrtales

Trees or shrubs; (plants Al-accumulators); included phloem +; (crystals/styloids +); leaves with 2 or 4 strong secondary veins, from (near) the base; K quincuncial, C contorted; anthers with branched vascular trace; pollen with pseudocolpi; carpels opposite petals, stigma punctate; outer and inner integuments ca 2 cells across; radicle bent.

188/5005. Very largely tropical, also subtropical. Two main groups below.

1. Olisbeoideae Burnett

Libriform septate fibres 0; (nodes 1:3); sclereids, inc. terminal foliar sclereids + (0); crystal styloids + (0); petiole bundle(s) arcuate, annular; (leaf veins lacking fibrous sheath); stomata paracytic; hairs 0 (uniseriate); stem apex frequently aborting, branching (complex) from previous flush; lamina vernation flat [Memecylon] or revolute [Mouriri], (2ndary veins pinnate), stipules + [seedlings]; inflorescence often fasciculate, pedicels articulated; flowers 4-5-merous, (K imbricate); A 2x K (straight - Votomita), dehiscing by pores to slits, anther endothecium +/0, connective with depressed elliptic oil-producing gland (0); ovary inferior, placentation basal, axile or parietal, stigma wet; ovules 1-18(-many)/carpel, apotropous, (outer integument 4-5 cells across - Mourira), parietal tissue ca 3 cells across; fruit a berry; seeds large, 1-5(-12), exotestal cells ± longitudinally elongated (some sclerotic hypodermal exotestal cells: Memecylon), exotegmen fibrous, massively sclerotic subhilum; embryo large (small), green, cotyledons thick, straight or curved, (crumpled - Memecylon); n = 7; hypocotyl elongated or not in germination, cotyledons lobed.

6/435: Memecylon (300), Mouriri (85). Tropical (map: from Morley 1976; Schatz 2001). [Photo - Flower, Fruit.]

Synonymy: Memecylaceae Candolle, Mouririaceae Gardner

2. Melastomatoideae Seringe

182[list]/4570. Largely tropical and subtropical, esp. South America, although ca 400 spp. endemic to the Caribbean. [Photo - Flower, Fruit, Fruit.]

2A. Pternandra

Cork cambium superficial; petiole bundle arcuate; stomata anomo-cyclocytic; hairs uniseriate; flowers 4-merous; endothecium in inner wall of inner sporangium only; carpel orientation?, placentation parietal [ovary divided by septae]; capsule fleshy.

1/15. Southeast Asia (map: based on Maxwell 1981).

Astronieae + The Rest: included phloem 0; petiole bundles variable; leaf veins lacking fibrous sheath; inflorescence often terminal; G developing before A; (K connate, calyptrate); anthers lacking endothecium, dehiscing by pores; carpels opposite K.

2B. Astronieae Triana

Cork cambium superficial; petiole bundle complex, open; stomata mostly anomocytic; hairs peltate scales; (anthers opening by slits); carpels opposite petals; placentation basal to basal-axile.

4/150: Astronidium (70), Astronia (60). Indomalesia and Pacific.

2C. THE REST

(Herbs; lianes, epiphytes); (cork cambium superficial); petiole bundle(s) arcuate or complex; stomata variable, poly- and cyclocytic, etc.; hair types very diverse, including short-stalked glands; flowers (3-)4-5(-10)-merous; K open [?level], (with alternating lobes; A (= and opposite sepals; = and opposite petals; many), with pores, 3 middle layers of wall with thickened cells, connective with a basal appendage or not, (staminodes +); (nectar produced from stamens); G 2-many, placentation axile, (style hollow; stigma capitate); ovule (1-few/carpel), outer integument ca 2 cells across, inner integument 2-3 cells across, parietal tissue 4-6 cells across, hypostase +: (fruit dehiscence irregular; baccate); n = (8-)9(-)12(-)17 (23, 31).

177/4305: Miconia (1000), Medinilla (400), Tibouchina (245), Sonerila (?180), Leandra (175), Clidemia (120), Gravesia (105), Microlicia (100), Tococa (50). Largely tropical and subtropical, esp. South America (map: from Quian & Ricklefs 2004; FloraBase 2007; Woodgyer 2007).

Synonymy: Blakeaceae Barnhart, Miconiaceae Martius, Rhexiaceae Dumortier

• Melastomataceae - Melastomatoideae are readily recognisable by their opposite, entire, exstipulate leaves with three or more strong veins ascending from at or near the base; tertiary veins are conspicuous, and run at right angles to the midrib. Hair types are notably diverse. The flowers are borne in branched, terminal inflorescences and have contorted and often somewhat stridently purple-pink petals; the porose anthers which invert during development and often have an elaborate, expanded connective, are distinctive. In old fruits, the walls often distintegrate, leaving vertical vascular bundles behind.

• Olisbeoideae have opposite, entire leaves and swollen nodes; the venation is variable, but indumentum is absent or consists of uniseriate hairs. The blade can be minutely punctate when held up to the light, or the surface may be minutely lineate - this is because of the sclereids common in the family (the surface may also dry minutely bumpy). The inflorescence is fasciculate and the rather small flowers are often blue (petals, stamens) and have inferior ovaries, but the parts are otherwise free, the calyx is valvate and there are twice as many stamens as petals; the anthers dehisce by slits and there are glands on the connectives. Most species are plants of the understorey.

Evolution. Divergence & Distribution. Renner et al. (2001, see also Renner & Meyer 2001, separation of Rhexia, etc.) suggested that crown group diversification in Melastomataceae began about 53 million years aho, but substantial diversification within the family did not begin until ca 30 million years ago, and movement into Africa did not occur until (18-)14(-10) million years ago. Morley and Dick (2003), on the other hand, were inclined to think that the broad outlines of diversification in the family could be linked with major tectonic (drift) events. Under this scenario - in 2003 a more established view than it is now - separation of the subfamilies occured ca 82 million years ago, and much diversification within the family, including the separation of the African/Malagasy clades, had occured before ca 68 million years ago, roughly when Madagascar and India separated. Clearly, these are incompatible scenarios. Renner (2004) again suggested that dispersal, not drift, was more likely, with separate Miocene dispersal events resulting in the species found on Madagascar, for example.

The diversity of Melastomataceae s.l. is centered in the tropical New World, Columbia alone having one third of the species and Brazil one half (Almeda et al. 2009). Bécquer-Granados et al. (2008) and Michelangeli et al. (2008b) discuss the complex biogeography of the speciose Antillean melastomes, while Goldenberg et al. (2008) find substantial geographical signal correlating with major clades in Miconia and its relatives.

Ecology. Epiphytes are quite common in Melastomatoideae, and some species are scramblers, whether with hook-shaped roots, or climbing with roots that attach to the support; some of the latter taxa have pseudodistichous leaves, one leaf of the pair being much reduced (Clausing & Renner 2001a).

Plant-Animal Interactions. Some species of Tococa live in close association with the ant Myrmelachista which creates mono- or oligospecific "devil's gardens" by injecting formic acid into the leaves of the surrounding vegetation, which is thus suppressed (Morawetz et al. 1992; Frederickson et al. 2005). Petiolar or laminar ant domatia are quite common in Blakeeae and Miconieae; in Maieta guianensis ca 80% of the host plant's nitrogen is derived from the waste deposited by the ant Pheidole minutula that lives in the domatia (Solano & Dejean 2004).

Floral Biology & Seed Dispersal. Monosymmetry of the flower is most evident in the androecium, and the stamens may form a serried rank on one side of the flower; I do not know the basic orientation of the flower. The petals of Melastomatoideae are usually more or less widely spreading, and buzz pollination is common, flowers being visited by many species of bees in search of pollen (Renner 1989; Harter et al. 2002). Different species of bees tend to visit different species of Melastomataceae, although the bees involved are not oligolectic; thus mass-flowering Miconia cinerascens in Brazil is visited by the stingless Melipona (Harter et al. 2002) which also visits other plants. However, some taxa have nectariferous anther connectives, or nectar is produced on the corolla (Medinilla), hypanthium, or even on the stigma or on top of the ovary (some Miconia), and in these cases the contorted petals form a tube and anthers often open by longitudinal slits (although lacking an endothecium?). Here pollination may be by birds (Renner 1989; Stein & Tobe 1989; Vogel 1997; Varassin et al. 2007, esp. 2008). However, Goldenberg et al. (2008) suggest rather more complex relationships between anther morphology and pollinator in Miconia and relatives. Pollination in Olisbeoideae is similar. There genera of Apidae and Anthophoridae collect material from the oil-producing anther glands, also collecting pollen by buzz pollination. Flowers with these glands (the great majority of species) are blue, rarely yellow, flowers without them are white (Buchmann & Buchmann 1981; Buchmann 1987).

Within Melastomatoideae, capsular fruits are linked with superior ovaries and fleshy fruits with inferior ovaries; fleshy fruits have arisen more than once (for the fleshy fruit of Miconia, see Cortez and Carmello-Guerreiro 2008). Fleshy fruits of Miconieae in the Colombian Andes provide a major resoirce for frugivorous birds (Kessler-Rios & Kattan 2012). A few taxa with dry, dehiscent fruits have inferior ovaries, and there the outer fruit wall may fall away, the fruit proper then functioning as an ordinary capsule (Michelangeli et al. 2008a); a group of these genera form a clade (Michelangeli et al. 2011: they also have stamens opposite the sepals).

Chemistry, Morphology, etc. The roots have anthocyanins. For wood anatomy, see van Vliet et al. (1981); vessel:ray pits are simple. Within Olisbeoideae, vessel:ray pits are half bordered, and the rays are 2-5 cells wide and heterocellular, compared to 1(-4) cells wide and homocellular elsewhere in this clade. For foliar sclereids, see Rao (1957, 1983). A survey of nodal anatomy is needed; split laterals are probably quite common (pers. obs., see also R. A. Howard in van Vliet & Baas 1975). In Dissochaeta and Pternandra there is a prominent stipular flange below the leaves in the interpetiolar position. vernation may seem to be plicate, perhaps because the secondary veins are so prominent; the leaves of Mouriri remain folded as they elongate. Little is known about floral development, although Wanntorp et al. (2011b) studied that ofConostegia, in which there has been increase in floral meristicy, and some other genera; stamen primordia opposite the petals may split.

The floral vasculature of Mouriri is distinctive (Morley 1976). Venkatesh (1955) found that the anthers of Memecylon had a normal endothecium, while in those of Mouriri the cells of the hypodermal layer had walls thickened all around.

Much other information is taken from Morley (1976: Olisbeoideae) and Renner (1993). For anatomical studies, see van Tieghem (1891a, b); for ovules, see Subramanyam (1942), and for seed morphology, see Groenendijk et al. (1996: Miconia) and Martin and Michelangeli (2009: Leandra). For general information, see Penneys (2004 onwards) Melastomataceae of the World.

Phylogeny. Mouriri + Memecylon are sister to Pternandra, in turn sister to a Melastomataceae s. str. in ndhF trees (Renner 1993); Morley (1953, 1976) had early suggested this general relationship. For a molecular phylogeny - in the context of morphology - of Melastomataceae, see Clausing and Renner (2001); see also Renner et al. (2001) and Renner (2004). Pternandra is probably sister to all other Melastomatoideae (Clausing & Renner 2001: moderately good support in a 3-gene analysis).

For a phylogeny of the fleshy-fruited and speciose - but paraphyletic - Miconieae, see Michelangeli et al. (2004) and Martin et al. (2008). Judd (1989) and Judd and Skean (1991) provide morphology-based phylogenetic analyses of axillary- and terminal-flowered Miconieae respectively. There members of different genera are considerably intermingled (Michelangeli et al. 2004; Martin et al. 2008; Goldenberg et al. 208), in part because of over-reliance on anther morphology for providing characters to delimit genera and sections that has turned out to be misplaced (Goldenberg et al. 2008). Generic limits in Merianeae are also difficult (Schulman & Hyvönen 2003). For the polyphyletic Leandra, see Martin et al. (2008), and for the African-Madagascan Warneckea, see Stone and Andreasen (2010). Recent broad summaries of phylogenies of neotropical melastomes provide an inkling of the new relationships (Guimaraes et al. 2010; Penneys & Judd 2010, esp. 2011, phylogenetic analysis of 111 morphological characters; Judd et al. 2010).

Stone (2006) provided a phylogeny of Olisbeoideae; the six morphologically-based genera all have molecular support.

Classification. The inclusion of Memecylaceae in Melastomataceae was an option in A.P.G. II, and this was formalized in A.P.G. III (2009). A tribal classification of Melastomatoideae awaits further sampling of New World taxa in particular, and it certainly cannot be based simply on variation in fruit types. However, this sampling has now been extended, and so tribal changes are beginning - e.g. Penneys et al. (2010: Henrieteeae), Michelangeli et al. (2011: Cyphostyleae).

Generic limits will also need much attention, as in Miconieae (Goldenberg et al. 2008 and references) and Merianeae (Schulman & Hyvönen 2003).

Thanks. I am grateful to S. Renner for comments.

[Crypteroniaceae [Alzateaceae + Penaeaceae]]: vessel-ray and vessel-parenchyma pits half bordered; stipules minute; stamens = and opposite petals; endothecium ephemeral; fruit a capsule; exotestal cells periclinally elongated, endotegmen not fibrous.

Evolution. Divergence & Distribution. Renner et al. (2001) thought that the age of the stem group of this clade was around 80 million years, although they suggested that diversification within it did not begin until ca 21 million years ago. Conti et al. (2002: calibration in part circular, based on drift events) estimated divergence of the two clades to have occured 141-106 million years ago, both it and later divergences showing a vicariant pattern reflecting continental drift. The estimate in Moyle (2004) is much younger, (78.6-)68(-57.4) million years. Morley and Dick (2003) estimated that the age of the clade was similar, ca 84 million years, but they thought that diversification of the major clades within it occured by ca 68 million years ago and that the current distributions of members of the clade reflect continental drift events.

Chemistry, Morphology, etc. Details of internal exine structure of Alzatea are similar to those of some Crypteroniaceae. Laterocytic stomata are known i.a. from Alzatea, Dactylocladus, and Rhynchocalyx (Baranova 1983). For pollen of much of this group, see Muller (1975), for anatomy - very variable - see van Vliet and Baas (1975: detailed comparison within Myrtales), for gross morphology, see van Beusekom-Osinga and van Beusekom (1975), and for perianth morphology, see Schönenberger and von Balthazar (2006). Some information on Crypteronia and relatives is taken from Tobe and Raven (1983b, 1987b) and Renner (2006b: general).

Phylogeny. Some of the relationships within this clade are only weakly supported (see Schönenberger & Conti 2003 for phylogeny and floral evolution of the whole group).

Classification. Van Beusekom-Osinga and van Beusekom (1975) included Alzateaceae and Rhynchocalycaceae in their expanded Crypteroniaceae, and this may make sense - lump the lot, other things being equal? The earliest name for the combined clade would be Penaeaceae, however, great expansion was deemed too radical, but Penaeaceae has been moderately broadened to include Oliniaceae and Rhynchocalycaceae (A.P.G. III 2009).

CRYPTERONIACEAE A.-L. de Candolle, nom. cons.   Back to Myrtales

Trees; plants Al-accumulators; cork also subepidermal; septate fibres 0, fiber pits bordered; nodes 3:3 [by split laterals], 1:3 with girdling bundles, cortical bundles ± developed or 0; sclereids +/0; petiole bundles annular (with medullary trace) or arcuate, wing bundles +; stomata paracytic (anomocytic - Dactylandra); hairs 0 (unicellular); lamina with 2ndary veins pinnate to palmate; plant polygamodioecious, or flowers bisexual; inflorescence racemose (spicate), with long branches; flowers 4-5-merous; C 0, 4-5; (A 2x K), connective thickened apically or not; (pollen bisyncolporate); G [2-6], ± inferior, placentation parietal or basal, (transseptal bundles +), style usu. slender, stigma capitate; ovules 1-3/carpel, nucellar tissue disintegrates early, (endothelium + - Axinandra); fruit a capsule, flattened or not, K deciduous; seeds many, endotesta crystalliferous, exotesta and endotegmen tanniniferous, other layers ± persistent; n = 8.

3/10. South East Asia, Malesia, Sri Lanka (map: from van Beusekom-Osinga 1977).

Evolution. Divergence & Distribution. Conti et al. (2002, see also Conti et al. 2004; Rutschmann et al. 2004, esp. 2007) suggest that Crypteronia and relatives rafted from Gondwana (Africa) to Asia via India, with an origin any time from the Early to Late Cretaceous, a later date being favoured (60-45 million years in Conti et al. 2002). Again, estimates in Moyle (2004) are much younger (48.6-)39(-29.4) million years, so drift would not be involved.

[Alzateaceae + Penaeaceae]: style stout.

ALZATEACEAE S. Graham   Back to Myrtales

Trees or shrubs; plants not Al accumulators, myricetin 0; vessel-ray and vessel-parenchyma pits simple; septate fibres +, fibre pits barely bordered; branches tending to be several together; nodes 3:3, cortical bundles +; sclereids +; petiole bundle annular and with wing bundles; stipules 0; flowers small, 5(-6)-merous; K pointed in bud, C rudimentary even in bud; anther thecae along apical margin of connective, connective wide, with backwards-directed appendage, filaments short; pollen pseudocolpi 0 [faint]; G [2], placentation intrusive parietal and with an incomplete septum, transseptal bundles +, stigma capitate; ovule with micropyle endostomal; megaspore mother cells several, embryo sac bisporic, eight nucleate [Allium-type]; capsule flattened, K persistent; seeds several, winged all around, with hair-pin bundle; exotestal cells low, with irregularly sinuous anticlinal walls, everything else collapsed; suspensor small; n = 14.

1/?2. Costa Rica to Peru (map: see Silverstone-Sopkin & Graham 1986). [Photo - Flowers.]

Chemistry, Morphology, etc. See Graham (1985, 2006) for general information on Alzatea.

PENAEACEAE Guillemin   Back to Myrtales

Trees or shrubs; lamina with glandular tip; parietal tissue 3-4 cells across; x = 10.

9/29. E. and S. Africa, overwhelmingly South African, and St Helena. 3 groups below.

1. Rhynchocalyx

Myricetin 0; septate fibres +, fibre pits barely bordered; branches tending to be several together; plants Al accumulators; cork cortical; petiole bundle arcuate, sclereids + [not in stem?]; leaves with glandular tips, stipules colleter-like; flowers 6-merous; K pointed, C clawed, lobed; A with 4 loculi opening separately, epidermis only persisting; G [2 (3)], placentation parietal, transseptal bundles +, stigma ± punctate; micropyle endostomal, nucellar cap ca 3 cells across; megaspore mother cells several; capsule flattened; seeds several, winged, embryo basal; exotesta tanniniferous, outer wall lignified, all coat cells persist.

1/1: Rhynchocalyx lawsonioides. South Africa, coastal Natal and Transkei.

Synonymy: Rhynchocalycaceae L. A. S. Johnson & B. G. Briggs

Penaeaeae + Olinieae: plants not Al accumulators; non-hydrolysable tannins +; hypanthium well developed, pollen grains psilate, foot layer and tectum thick; exotegmen fibrous; embryo suspensor 0.

2. Peneaeae de Candolle

Small ericoid shrubs; libriform septate fibres 0; mesophyll with (spirally thickened) fibres; leaves often sessile, stipules ± colleter-like; flowers axillary, 4-merous; K petaloid, C 0, (A straight in bud; connective with branched vascular bundle); G 4, opposite petals, style also filiform, stigma capitate or lobed; ovules 2-4(-many)/carpel; embryo sac tetrasporic, 16-celled [i>Penaea type]; fruit a capsule; seeds with funicular elaiosome; exotestal cells much developed or endotestal cells much elongated, other layer crushed, endotegmen fibrous[?]; chalazal ["basal"] endosperm haustorium +, embryo with large hypocotyl, cotyledons tiny.

7/23: Stylapterus (8). South Africa, S. and S.W. parts of the Cape. [Photo - Habit.]

Synonymy: Henslowiaceae Lindley, Plectroniaceae Hiern

3. Olinieae Horaninow

Cork subepidermal; stomata variable; stipules cauline-on leaf base; flowers (4-)5-merous; ?epicalyx +, small, K ± spatulate, C concave, thick, hairy; pollen heteropolar; G [(2-)4-5], inferior, opposite sepals, transseptal bundles +, stigma ± clavate, (commissural); ovules 2-10/carpel, apotropous, campylotropous, outer integument ca 5 cells across, chalaza strongly vascularized, hypostase +; fruit drupaceous, 1-seeded, K not persisting; seed usually single; exotegmic cells fibrous; cotyledons spirally twisted or irregularly folded; n = 12, ?15, ?20.

1/5. Africa, St. Helena. [Photo - Fruit, Flowers.]

Synonymy: Oliniaceae Harvey & Sonder

• The stems of Penaeaceae are square, sometimes ridged, and the nodes are swollen.

Evolution. Floral Biology & Seed Dispersal. Many Penaeaeae have ant-dsipersed seeds (Lengyel et al. 2010).

Chemistry, Morphology, etc. The vegetative anatomy of Peneaeae is undistinguished, but the embryo sac of Penaea, at least, is unique. Nectar is secreted from the base of the hypanthium. Crushed or broken plant parts of Olinieae smell of almonds; they contain the cyanogenic glucoside, prunasin. The ovules have been reported as being apotropous and ascending (Baillon 1877). The interpretation of the perianth of Olinia is a matter of some dispute; here I follow the interpretation offered by Schönenberger and Conti (2003), although the exact nature of the outer whorl of very small appendages is still unclear (described as "?epicalyx" above). The haploid chromosome number of Olinia is 12, according to Takhtajan (1997), but cf. Goldblatt (1976).

See Schönenberger (2006) for general information about Rhynchocalyx; for general embryology, see Tobe and Raven 1984b, c, 1985b), for the embryo suspensor of Penaea and relatives, see Ross and Sumner (2005), and for general information, see Schönenberger et al. (2006); and for general information about Olinia, see von Balthazar and Schönenberger (2006).